I frequently have to restart my computer in order to get sound on videos.

For noo apparent reason, i frequently have to reboot in order to get the sound to work on videos.  I've tried uninstalling and reinstalling flashplayer.  I'm using Windows 7, 32 bit, and have the latest version of the player.  There is no error message which means the player should be working right, but it's not dependable.  WHY!!